I havent found a lot of information re' removing smog and airboxs that slow the bike down..but I am new to Fi. On my current bike aftermaket exhaust, air box removal, o2censor, smog stuff and aftermarket air box and you were talking A LOT of added HP! but with the GSA it seems in terms of modifying the engine or 'un-corking' it their is not much to be done?